000 AXPZ20 KNHC 091605 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Wed Sep 9 2020 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1545 UTC. ...TROPICAL WAVES... A tropical wave has its axis along 103W from 04N to 18N. It is moving westward at 15 kt. Scattered moderate to strong convection is within 30 nm of a northwest to southeast line that extends from 13N101W to 14N104W to 16N105W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from the coast of Colombia near 11N74W to across southern Nicaragua, then continues northwestward to 13N90W and to 14N100W to 18N105W to low pressure near 19N114W 1007 mb and southwestward to 14N120W to 13N130W and to west of the area at 12N140W. Scattered moderate to isolated strong convection is within 120 nm south of the trough between 118W-123W and within 60 nm south of the trough between 123W-125W. Scattered moderate convection is within 60 nm south of the trough between 129W-136W, and also within 30 nm south of the trough between 89W-90W and between 92W-95W. Similar activity is within 30 nm north of the trough between 116W-117W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Satellite imagery shows a large area of disturbed weather that extends from near the coast of southern Mexico to well offshore that coast. The area consists of the tropical wave that is along 103W as described above. In addition, clusters of scattered moderate to isolated strong convection are noted from 13N to 16N between 93W-97W. This area has potential for some gradual development through early next week while it moves slowly west- northwestward away from the coast of Mexico. Otherwise, a cold front has dipped down to over the northern Gulf of California. It extends from a 1002 mb low over southeastern Arizona. The cold front extends northwestward to just inland the coast of northern Baja California. Fresh to strong northwest to north winds are behind the front north of 30N. These winds will build seas briefly to just below 8 ft this morning as high pressure settles in over the Great Basin area. Winds diminish and seas subside this afternoon as the high pressure begins to shift eastward and weaken. Mainly light to gentle west to northwest winds will continue through the end of the week across the offshore waters west of Baja California. Seas of 4-6 ft there will subside slightly on Thu and change little through Fri night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate southwest winds will prevail south of the monsoon trough axis through the weekend, while light and variable winds are expected north of it. The trough is expected to meander west of Nicaragua for the next few days. Seas will be in the 5-7 ft range in long-period southerly swell. REMAINDER OF THE AREA... Low pressure of 1007 mb is centered near 19N114W. This low is along the monsoon trough as described above. First few visible satellite images show a small cyclonic circulation with this low. The imagery also shows scattered moderate to isolated strong convection within 90 nm of the low in the SW quadrant. Environmental conditions are expected to be only marginally conducive for development of this system during the next several days while it moves slowly westward. This system has a low chance of tropical cyclone formation through 5 days. Otherwise, high pressure dominates the waters north of 20N, west of 120W. Gentle to moderate trade winds continue north of the monsoon trough axis. Moderate to fresh southerly flow persists south of the trough, with isolated areas of 7-8 ft seas. Long- period southerly swell is spreading northward across the region E of 120W, reaching the offshore forecast waters of Mexico, Central America, Colombia and Ecuador with seas in the 5-7 ft range. Seas will slightly subside through Fri. $$ Aguirre